IMU Rotation Vector¶
This example shows rotation vector output at 400 hz rate using the onboard IMU. Returns quaternion.
Demo¶
Example script output
~/depthai-python/examples$ python3 imu_rotation_vector.py
Rotation vector timestamp: 0.000 ms
Quaternion: i: 0.089355 j: 0.355103 k: 0.034058 real: 0.929932
Accuracy (rad): 3.141602
Rotation vector timestamp: 3.601 ms
Quaternion: i: 0.088928 j: 0.354004 k: 0.036560 real: 0.930298
Accuracy (rad): 3.141602
Rotation vector timestamp: 6.231 ms
Quaternion: i: 0.094604 j: 0.344543 k: 0.040955 real: 0.933105
Accuracy (rad): 3.141602
Setup¶
Please run the install script to download all required dependencies. Please note that this script must be ran from git context, so you have to download the depthai-python repository first and then run the script
git clone https://github.com/luxonis/depthai-python.git
cd depthai-python/examples
python3 install_requirements.py
For additional information, please follow installation guide
Source code¶
Also available on GitHub
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 | #!/usr/bin/env python3 import cv2 import depthai as dai import time import math # Create pipeline pipeline = dai.Pipeline() # Define sources and outputs imu = pipeline.create(dai.node.IMU) xlinkOut = pipeline.create(dai.node.XLinkOut) xlinkOut.setStreamName("imu") # enable ROTATION_VECTOR at 400 hz rate imu.enableIMUSensor(dai.IMUSensor.ROTATION_VECTOR, 400) # it's recommended to set both setBatchReportThreshold and setMaxBatchReports to 20 when integrating in a pipeline with a lot of input/output connections # above this threshold packets will be sent in batch of X, if the host is not blocked and USB bandwidth is available imu.setBatchReportThreshold(1) # maximum number of IMU packets in a batch, if it's reached device will block sending until host can receive it # if lower or equal to batchReportThreshold then the sending is always blocking on device # useful to reduce device's CPU load and number of lost packets, if CPU load is high on device side due to multiple nodes imu.setMaxBatchReports(10) # Link plugins IMU -> XLINK imu.out.link(xlinkOut.input) # Pipeline is defined, now we can connect to the device with dai.Device(pipeline) as device: def timeDeltaToMilliS(delta) -> float: return delta.total_seconds()*1000 # Output queue for imu bulk packets imuQueue = device.getOutputQueue(name="imu", maxSize=50, blocking=False) baseTs = None while True: imuData = imuQueue.get() # blocking call, will wait until a new data has arrived imuPackets = imuData.packets for imuPacket in imuPackets: rVvalues = imuPacket.rotationVector rvTs = rVvalues.getTimestampDevice() if baseTs is None: baseTs = rvTs rvTs = rvTs - baseTs imuF = "{:.06f}" tsF = "{:.03f}" print(f"Rotation vector timestamp: {tsF.format(timeDeltaToMilliS(rvTs))} ms") print(f"Quaternion: i: {imuF.format(rVvalues.i)} j: {imuF.format(rVvalues.j)} " f"k: {imuF.format(rVvalues.k)} real: {imuF.format(rVvalues.real)}") print(f"Accuracy (rad): {imuF.format(rVvalues.rotationVectorAccuracy)}") if cv2.waitKey(1) == ord('q'): break |
Also available on GitHub
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 | #include <cstdio> #include <iostream> #include "utility.hpp" // Includes common necessary includes for development using depthai library #include "depthai/depthai.hpp" int main() { using namespace std; using namespace std::chrono; // Create pipeline dai::Pipeline pipeline; // Define sources and outputs auto imu = pipeline.create<dai::node::IMU>(); auto xlinkOut = pipeline.create<dai::node::XLinkOut>(); xlinkOut->setStreamName("imu"); // enable ROTATION_VECTOR at 400 hz rate imu->enableIMUSensor(dai::IMUSensor::ROTATION_VECTOR, 400); // it's recommended to set both setBatchReportThreshold and setMaxBatchReports to 20 when integrating in a pipeline with a lot of input/output connections // above this threshold packets will be sent in batch of X, if the host is not blocked and USB bandwidth is available imu->setBatchReportThreshold(1); // maximum number of IMU packets in a batch, if it's reached device will block sending until host can receive it // if lower or equal to batchReportThreshold then the sending is always blocking on device // useful to reduce device's CPU load and number of lost packets, if CPU load is high on device side due to multiple nodes imu->setMaxBatchReports(10); // Link plugins IMU -> XLINK imu->out.link(xlinkOut->input); dai::Device d(pipeline); auto imuQueue = d.getOutputQueue("imu", 50, false); auto baseTs = steady_clock::now(); while(true) { auto imuData = imuQueue->get<dai::IMUData>(); auto imuPackets = imuData->packets; for(auto& imuPacket : imuPackets) { auto& rVvalues = imuPacket.rotationVector; auto rvTs = rVvalues.getTimestampDevice() - baseTs; printf("Rotation vector timestamp: %ld ms\n", static_cast<long>(duration_cast<milliseconds>(rvTs).count())); printf( "Quaternion: i: %.3f j: %.3f k: %.3f real: %.3f\n" "Accuracy (rad): %.3f \n", rVvalues.i, rVvalues.j, rVvalues.k, rVvalues.real, rVvalues.rotationVectorAccuracy); } int key = cv::waitKey(1); if(key == 'q') { return 0; } } return 0; } |
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